(1) Field of the Invention
This invention relates to an automatically foldable and unfoldable album or book assembly and, more particularly, to such an album which includes a plurality of foldable sheets joined together in a strip fashion.
(2) Description of the Prior Art
Foldable sheets, which may be collapsed or folded together so as to occupy a fraction of the space occupied in the unfolded state, are well known in the prior art. A variety of foldable sheet configurations have been developed and examples of these are shown in U.S. Pat. Nos. 2,525,937; 3,753,558 and 4,502,711. These sheets are automatically unfolded and folded when opened and closed. The use of a strip type of configuration for books, greeting cards and the like is also well known in the prior art. Examples of these arrangements are shown in U.S. Pat. Nos. 1,531,065; 2,546,878; 2,615,732; 2,824,394; and 4,289,333. While the maps shown in U.S. Pat. Nos. 1,53l,065; 2,615,732 and 4,289,333 are also partially folded, these are simple folds and these maps do not automatically unfold and fold when opened and closed.
It is an object of the present invention to provide a book or album which has foldable sheets which are automatically unfolded and folded when the book is opened and closed, but which also has a plurality of sheets joined together in a strip fashion.
It is another object of the present invention to provide such an album in which each foldable sheet is automatically folded and unfolded with a single turn.
It is a further object of the present invention to provide such an album in which, with a single turn, a subsequent sheet is unfolded automatically while the immediately preceding sheet is being closed.
It is yet another object of the present invention to provide such an album which is easy to use, which is inexpensive and simple to manufacture, and which can be provided in a variety of attractive shapes and configurations.